Ground Transport
Here are typical rates for airport transportation by taxi from these airports to Niagara Falls:

Buffalo International Airport $60 USD

Toronto International Airport $145 Cdn

Hamilton International Airport $95 Cdn

Buffalo to Toronto Airport area $168 USD

Pearson Airport to Buffalo $219 Cdn

Niagara International Airport
The Niagara Falls International Airport, 4 miles east of Niagara Falls and north of Buffalo, handles international charter and cargo service, and functions as the reliever airport for the region (for Greater Buffalo International Airport). It has the fourth longest runway in New York State, at 2994 meters (9,825 feet), which enables it to accommodate all commercial aircraft. The airport is also home to the Niagara Falls Air Force Reserve and the New York Air National Guard. The NFIA is located right off Route 62, which connects easily with U.S. Interstate 90 and the 405 in Canada.

Niagara Falls International Airport ("IAG") opened in 1928 as a city-owned municipal airport, and expanded in the early 1940s, after the Bell Aerospace plant built the first commercial helicopter and the world's first super sonic plane in Niagara Falls. The airport also became home to an Air Reserve Base, which became the upstate home of the New York Air National Guard. In 1959, the main runway was extended to over 9,000 feet in order to accommodate the new, more demanding military aircraft, and in 2003, the runway was lengthen again, to 2994 meters (9,825 feet), enabling the NFIA to accommodate anything flying. In 1965 U.S. Customs approved it for international flights, and in 1970 the Niagara Frontier Transportation Authority purchased the airport from the City of Niagara Falls.

St Catharines - Niagara District Airport
St Catharines - Niagara District Airport (CYSN*/YCM) has all the facilities of a major airport, 24 hour customs availability, and no curfew. The main runway is 5000 ft (1524m). The airport was opened in 1929 on the eastern edge of the City of St. Catharines (adjacent to the Welland Canal), and in 1935 was relocated 3 miles northeast to its present location. The airport is also home to the St. Catharines Flying Club, and during World War II, the airport was deeded to the Federal Government and served as part of the British Commonwealth Air Training Plan.